Glad you asked. The dictionary states - "suitable or fit to be printed or published".
Simply put - I design it and email it to you ready to print (or it could be a direct download if you buy a printable party package here). Then you print it out at home (or at a printer - you could go to Officeworks here in Australia - just that I don't print it for you).
Make sense? I design it. You print it. So it's printable.
Heads up! Printables can also be known as downloads, templates or digital files across various websites too.
Comment below if you have any questions. I am always here to help answer your questions no matter how "dumb" you think they are. There is no dumb question. I am here to help you DIY.